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Solar Physics

, Volume 160, Issue 1, pp 79–96 | Cite as

Delay between the circularly polarized components in fine structures during solar type IV events

  • G. P. Chernov
  • P. Zlobec
Article
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Abstract

We analyzed intermediately polarized (20–80%) fine structures (pulsations, sudden reductions, fiber bursts and zebras) that were recorded in type IV events. The mean polarization degree was practically the same for all the fine structures recorded in an interval lasting a few minutes and it was similar to the polarization of the continuum. A detailed analysis during the evolution of single structures reveals changes in polarization (in particular an ‘undulation’ at flux density minima) even stronger than 20%. They were caused by a delay, up to 0.1 s, between the two circularly polarized components. The weaker polarimetric component was delayed in 2 sets and the stronger one in 1 set. In the event of April 24, 1985 different types of fine structures were sporadically detected in more than one hour long time interval. Short delays of the stronger or of the weaker component were sometimes observed.

The events characterized by fine structures are generally totally polarized in the ordinary mode. We assume that this holds also for the phenomena studied here. The observed intermediate polarization therefore requires a depolarization due to propagation effects. We discuss the mode coupling and the reflection of the original radio signal that could also generate the delay of the weaker and the stronger component respectively. The possibility of polarization variation due to the change of the angle between the direction of the propagation and the magnetic field in a quasi-transversal region and in a low intensity magnetic field in a current sheet is also given.

Keywords

Fine Structure Current Sheet Mode Coupling Radio Signal Intensity Magnetic Field 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • G. P. Chernov
    • 1
  • P. Zlobec
    • 2
  1. 1.IZMIRANTroitsk, Moscow RegionRussia
  2. 2.Trieste Astronomical ObservatoryTriesteItaly

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